Re: the suggestion of a bedroom, note that the original poster said they were sold out. Thus, it's either a roomette or a coach ticket. The bedrooms on the Viewliner trains sell out quickly because there's only two per sleeper car.
I should have realized that the Crescent runs Viewliners and yes on these trains the bedrooms are few and far between. Same on the LSL . I believe that there are only 4 bedrooms on each of those trains but the roomettes do have a potty and a sink. As long as they limit the carry on luggage to one overnight bag each they can make due in a roomette.